Excision Completion

Bungie's triumph list has Still Have Reserves? for defeating the Witness in Excision and Shape of Finality for the Grandmaster clear. The record for the Ergo Sum Catalyst says it is acquired from completing Excision on Grandmaster. Ergo Sum is an exotic sword that drops with one of eight exotic traits, Gathering Light and Wolfpack Rounds among them, and one of five sword frames, such as the Wave Sword Frame with its shockwave uppercut; its fixed Transcendent Duelist perk adds damage while Transcendent and lengthens Transcendence. The campaign around the mission is also what opens Prismatic; Bungie says Prismatic Aspects and Fragments come from main missions, adventures and side missions in the Pale Heart.

• Excision completed on Normal or Grandmaster, for 1 to 15 runs.
• The Ergo Sum catalyst from a Grandmaster clear.
• Optional triumph goals, including a 3-Phase Kill choice and a Self-play (Sherpa) extra.
• Normal, Express or Super Express speed.

• The Final Shape expansion, which Destiny 2: The Collection includes.
• The Final Shape campaign finished up to the Excision mission.

Which triumphs does the mission have?

Still Have Reserves? and Shape of Finality. The Pale Heart seal Transcendent, with 11 triumph records, also includes Shape of Finality.

What kind of weapon is Ergo Sum?

A Kinetic exotic sword that uses special ammo and sits in the energy slot.

Does Bungie still list Grandmaster?

Yes. Bungie's game data still holds an "Excision: Grandmaster" activity, and Grandmaster is also a Portal Ops difficulty whose S grade maps to Tier 5 gear.